21. The prisoner was ______ of his civil liberty for three years.
A) discharged
B) derived
C) deprived
D) dispatched
22. Small farms and the lack of modern technology have ______ agricultural production.
A) blundered
B) tangled
C) bewildered
D) hampered
23. The Japanese scientists have found that scents ______ efficiency and reduce stress among office workers.
A) enhance
B) amplilf
C) foster
D) magnify
24. All the students have to ______to the rules and regulations of the school.
A) confirm
B) confront
C) confine
D) conform
25. He ______ his head, wondering how to solve the problem.
A) scrapped
B) screwed
C) scraped
D) scratched
26. As soon as the boy was able to earn his own living he ______ his parents' strict rules.
A) defied
B) refuted
C) excluded
D) vetoed
27. The helicopter _____ a light plane and both pilots were killed.
A) coincided with
B) stumbled on
C) tumbled to
D) collided with
28. To ______ is to save and protect, to leave what we ourselves enjoy in such good condition that others may also share the enjoyment.
A) conserve
B) conceive
C) convert
D) contrive
29. Put on dark glasses or the sun will ______ you and you won' t be able to see.
A) discern
B) distort
C) distract
D) dazzle
30. In ______ times human beings did not travel for pleasure but to find a more favourable climate.
A) prime
B) primitive
C) primary
D) preliminary